Actuator, electric motor and associated method

ABSTRACT

An electrical switch for an electric machine includes body, a stator fixedly secured to the body and a rotor. The actuator includes a first member securable to the rotor and rotatable with it. The actuator also includes a second member, a first electrically conductive member cooperates with the second member. The actuator also includes a second electrically conductive member. The second electrically conductive member is spaced from said first electrically conductive member when said first electrically conductive member is in the first axial position and electrically engaged with said first electrically conductive member when said first electrically conductive member is in the second axial position.

BACKGROUND OF THE INVENTION

The embodiments described herein relate generally to an electricmachine, and more specifically, to an electric machine with a switchactivated or deactivated when a rotational speed is obtained.

An electric machine is typically in the form of an electric generator oran electric motor. The machine typically has a centrally located shaftthat rotates relative to the machine. Electrical energy applied to coilswithin the machine initiates this relative motion which transfers thepower to the shaft and, alternatively, mechanical energy from therelative motion of the generator excites electrical energy into thecoils. For expediency, the machine will be described hereinafter as amotor. It should be appreciated that a machine may operate as agenerator and vice versa.

A stationary assembly, also referred to as a stator, includes a statorcore and coils or windings positioned around portions of the statorcore. It is these coils to which energy is applied to initiate thisrelative motion which transfers the power to the shaft. These coils areformed by winding wire, typically copper, aluminum or a combinationthereof, about a central core to form the winding or coil. An electriccurrent is directed through the coils which induces a magnetic field. Itis the magnetic field that initiates this relative motion whichtransfers the power to the shaft.

For a variety of reasons an electrical machine may have a centrifugalswitch that is used to either electrically engage or electricallydisengage a circuit when a certain rotational speed is obtained. Suchswitches typically have a mechanical component or components that areurged radially outward by centrifugal forces that increase as therotational speed increase. The centrifugal forces move contacts in theelectrical circuit either into engagement or disengagement when therotational speed reaches a certain level. The mechanical components thatmove the contacts are expensive and are subject to mechanical wear.

One such centrifugal switch is used in induction motors to disengage thestart winding once the motor has obtained a sufficiently high rotationalspeed that the run windings can properly power the motor. Such asufficient motor speed may be, for example about 70% of the maximummotor speed.

The present invention is directed to alleviate at least some of theseproblems with the prior art.

BRIEF DESCRIPTION OF THE INVENTION

A switch according to the present invention may be used in an electricmachine that is typically in the form of an electric generator or anelectric motor. The motor includes a housing and a centrally locatedrotor that rotates relative to and is secured to the housing. The motoralso includes a stator secured to the housing. The stator includes aplurality of spaced apart teeth extending inwardly. The stator alsoincludes wire formed into a plurality of coils, each of the plurality ofcoils wrapped around one of the plurality of teeth.

For example, the motor may be in the form of an induction, capacitivestart, motor. The motor includes a first set of coils that is used tooperate the motor in a run mode and a second set of coils that iselectrically connected to a start capacitor that is used to operate themotor in a start mode. Once the motor reaches 70% of the motor maximumspeed, the start coils are deenergized with, for example, an electricaldevice or switch, for example, the centrifugal switch of the presentinvention.

According to an aspect of the present invention, an electrical switchfor use in an electric machine may include a first member securable tothe rotor and rotatable with the rotor. The switch may also include asecond member slidably securable to the body and configured to bemoveable with respect to the first member in a direction parallel to theaxis of rotation of the rotor. The first member and the second memberare either magnetically attracted toward or magnetically repelled fromeach other.

The switch may also include a first electrically conductive membercooperable with the second member and moveable in a direction parallelto the axis of rotation of the rotor from a first axial position to asecond axial position, spaced from the first axial position. The secondmember may be adapted to urge the first electrically conductive memberfrom the first axial position to the second axial position.

The switch may also include a second electrically conductive memberspaced from the first electrically conductive member when the firstelectrically conductive member is in the first axial position andelectrically engaged with the first electrically conductive member whenthe first electrically conductive member is in the second axialposition. The first member may have a least a portion thereof having acenter of mass moveable from a first radial distance from the axis ofrotation of the rotor when the rotor rotates at a first rotational speedto a second radial distance from the axis of rotation of the rotor whenthe rotor rotates at a second rotational speed different than the firstrotational speed. The second radial distance is different than the firstradial distance.

Magnetic attraction or magnetic repulsion may cause the first member andthe second member to be either magnetically attracted toward each otheror magnetically repelled away from each other to cause to cause thesecond member to either engage and disengage the first electricallyconductive member with the second electrically conductive member whenthe rotor reaches the second rotational speed.

According to an aspect of the invention, the electrical switch may beconfigured such that the first member and the second member aremagnetically repelled by each other.

According to another aspect of the invention, the electrical switch maybe configured such that at least one of a portion of the first memberand a portion of the second member includes a magnet.

According to another aspect of the invention, the electrical switch maybe configured such that the first member includes a base fixedly securedto the end of the rotor, an arm having an end extending from the base atleast partially in a direction parallel to the axis of rotation of therotor, and one of a magnet and a ferrous material connected to the endof the arm and spaced from the base.

According to another aspect of the invention. the electrical switch maybe configured such that the first member includes a plurality of spacedapart arms, each arm having a first end thereof and one of a magnet anda ferrous material connected to the first end of each of the pluralityof arms.

According to another aspect of the invention, the electrical switch maybe configured such that wherein each of the spaced apart arms areequally spaced apart with respect to the axis of rotation of the rotor.

According to another aspect of the invention, the electrical switch maybe configured such that the second member includes a first componentfixedly secured to the body a second component slidably secured to thefirst component, and one of a magnet and a ferrous material secured tothe second component.

According to another aspect of the invention, the electrical switch maybe configured such that the first component includes a cylindricalsleeve; and wherein the second component includes a cylindrical rod.

According to another aspect of the invention, the electrical switch maybe configured such that the first electrically conductive memberincludes a resilient metal having a first end connected to the body anda second cantilevered end engagable with the second member and whereinthe second electrically conductive member includes a resilient metalhaving a first end connected to the body and a second cantilevered endengagable with the first electrically conductive member.

According another aspect of the invention, the electrical switch may beconfigured such that the first member includes a first componentincluding a base fixedly secured to the end of the rotor, first andsecond legs, each leg extending at least partially axially outwardlyfrom one of the distal ends of the planar base and first and secondplanar arms extending at least partially radially inwardly from thedistal ends of the legs, one of a magnet and a ferrous materialconnected to the first arm, and the other of one of a magnet and aferrous material connected to the second arm.

According to another aspect of the invention, the electrical switch maybe configured such that the ferrous material is permanently magnetized.

According to another aspect of the invention, the electrical switch maybe configured such that the first component is made from a plurality ofindividual members, wherein the first arm is connected to the first legby a mechanical hinge, and further including a spring connected to thefirst leg and to the second arm, the spring adapted to permit the firstarm to move outwardly about the hinge when the rotor is rotated.

According to another aspect of the invention, the electrical switch maybe configured such that the first member includes a first member magnet;and further including a third member including a third member magnet,the third member connected to the first member, the third member magnetpositioned farther than first member magnet from the second member.

According to another aspect of the invention. the electrical switch maybe configured such that the first member includes an integral metalcomponent having a planar base fixedly secured to the end of the rotor,first and second planar legs, each leg extending at least partiallyaxially outwardly from one of the distal ends of the planar base andfirst and second planar arms extending at least partially radiallyinwardly from the distal ends of the planar legs, a first magnetconnected to the first arm, and a second magnet connected to the secondarm.

According to another aspect of the invention. the electrical switch mayfurther include a third magnet positioned on the planar base of thecomponent.

According to another aspect of the invention, the electrical switch maybe configured such that the first member includes a plurality of spacedapart arcuate magnet portions spaced from the axis of rotation of therotor and wherein the second member has a centerline parallel to andspaced from the axis of rotation of the rotor.

According to an aspect of the invention, an electric machine may beprovided. The machine includes a housing, a stator and a rotor. Thehousing has an inner surface defining a cavity therein. The stator issecured to the housing. The rotor is rotatably secured to the housingand defines an axis of rotation thereof. The machine also includes acentrifugal switch including a first member securable to the rotor androtatable therewith and a second member slidably securable to the bodyand configured to be moveable with respect to the first member in adirection parallel to the axis of rotation of the rotor. The firstmember and the second member are one of magnetically attracted toward ormagnetically repelled from each other. The machine also includes a firstelectrically conductive member cooperable with the second membermoveable in a direction parallel to the axis of rotation of the rotorfrom a first axial position to a second axial position, spaced from thefirst axial position. The second member is adapted to urge the firstelectrically conductive member from the first axial position to thesecond axial position.

The machine also includes a second electrically conductive member spacedfrom the first electrically conductive member when the firstelectrically conductive member is in the first axial position andelectrically engaged with the first electrically conductive member whenthe first electrically conductive member is in the second axialposition.

The first member has a least a portion thereof having a center of massmoveable from a first radial distance from the axis of rotation of therotor when the rotor rotates at a first rotational speed to a secondradial distance from the axis of rotation of the rotor when the rotorrotates at a second rotational speed different than the first rotationalspeed. The second radial distance is different than the first radialdistance.

One of the of magnetic attraction and the magnetic repulsion causes thefirst member and the second member to be one of magnetically attractedtoward each other or magnetically repelled away from each other to causeto cause the second member to one of engage and disengage the firstelectrically conductive member with the second electrically conductivemember when the rotor reaches the second rotational speed.

According to another aspect of the invention, the electrical machine maybe configured such that the first member and the second member aremagnetically repelled by each other.

According to an aspect of the invention the electrical machine may beconfigured such that at least one of a portion of the first member and aportion of the second member includes a magnet.

According to an aspect of the invention a method for transmitting anelectrical signal in an electric machine once a certain rotation speedhas been obtained is provided. The method includes the steps ofproviding a housing, securing a stator to the housing, and rotatablysecuring a rotor to the housing. The rotor defines an axis of rotationthereof.

The method also includes the steps of providing a centrifugal switch,securing a first member to the rotor, and slidably securing a secondmember to the housing.

The method also includes the steps of configuring the second member tobe moveable with respect to the first member in a direction parallel tothe axis of rotation of the rotor, adapting the first member and thesecond member to be one of magnetically attracted toward or magneticallyrepelled from each other, and providing a first electrically conductivemember.

The method also includes the steps of using the second member toselectively move the first electrically conductive member from the firstaxial position to the second axial position, providing a secondelectrically conductive member spaced from the first electricallyconductive member when the first electrically conductive member is inthe first axial position, and electrically engaging with the firstelectrically conductive member to the second electrically conductivemember when the first electrically conductive member is in the secondaxial position.

The method includes the steps of providing a portion of the first memberhaving a center of mass moveable from a first radial distance from theaxis of rotation of the rotor when the rotor rotates at a firstrotational speed to a second radial distance from the axis of rotationof the rotor when the rotor rotates at a second rotational speeddifferent than the first rotational speed, the second radial distancebeing different than the first radial distance.

The method also includes the steps of utilizing one of the of magneticattraction and the magnetic repulsion to cause one of the first memberand the second member to be one of magnetically attracted toward eachother or magnetically repelled away from each other to cause the secondmember to engage the first electrically conductive member with thesecond electrically conductive member when the rotor reaches one of thefirst rotational speed and the second rotational speed. The inner cavityis generally cylindrical and wherein the moisture guide is generallyplanar.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view partially in cross-section of an electricmotor according to an embodiment of the present invention;

FIG. 2 is partial perspective view of the electric device of FIG. 2 ofan electric device according to an embodiment of the present inventioninstalled in the electric motor of FIG. 1 with the motor with the motorat a first or zero rotational speed and with the device in a firststate;

FIG. 3 is partial perspective view of the electric device of FIG. 2 withthe motor at a second or third rotational speed, faster than the firstrotational speed and with the device in a second state;

FIG. 3A is partial plan view of the electric device of FIG. 2 showingthe first member base in a first rotational speed position in solidlines, in a second rotational speed position in dashed lines and in athird rotational speed position in phantom lines;

FIG. 4 is partial perspective view of a magnet and bracket assembly foruse in the electric device of FIG. 3 with the lower magnets closetogether to urge the upper magnet upwardly;

FIG. 5 is partial perspective view of the magnet and bracket assembly ofFIG. 3 with the lower magnets moved apart by centrifugal force to permitthe upper magnet to move downwardly;

FIG. 6 is a partial perspective view of a magnet and bracket assemblyaccording to another embodiment of the present invention utilizing semicylindrically shaped magnets;

FIG. 7 is a partial perspective view of a magnet and bracket assemblyaccording to another embodiment of the present invention utilizingrectangularly shaped magnets;

FIG. 8 is a partial perspective view of a magnet and bracket assemblyaccording to another embodiment of the present invention utilizing threecylindrically shaped magnets;

FIG. 9 is a partial perspective view of a magnet and bracket assemblyaccording to another embodiment of the present invention utilizing fourcylindrically shaped magnets;

FIG. 10 is a partial perspective view of a magnet and bracket assemblyaccording to another embodiment of the present invention utilizing twocylindrically shaped magnets on the bracket and two cylindrically shapedmagnets centrally positioned to cooperate with the magnets on thebracket;

FIG. 11 is a partial perspective view of a magnet and bracket assemblyaccording to another embodiment of the present invention utilizing twocylindrically shaped magnets on the bracket and a third cylindricallyshaped magnet centrally positioned, and configured to have the magnetsattract each other when cooperating with each other,

FIG. 12 is a partial perspective view of a magnet and bracket assemblyaccording to another embodiment of the present invention utilizing ahollow cylindrical magnet, made from 6 magnet sectors on the bracket andan offset cylindrically shaped magnet to cooperate with the magnets onthe bracket; and

FIG. 13 is a partial plan view of a magnet and bracket assemblyaccording to another embodiment of the present invention utilizing amechanical hinge and spring to urge the magnets together whencentrifugal forces are low; and

FIG. 14A is a first part of three parts of a flow chart of anotherembodiment of the present invention in the form of a method forproviding an electric device;

FIG. 14B is a second part of three parts of a flow chart of anotherembodiment of the present invention in the form of a method forproviding an electric device; and

FIG. 14C is a third part of three parts of a flow chart of anotherembodiment of the present invention in the form of a method forproviding an electric device.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, an electric machine 10 for which a switch accordingto the present invention may used is shown. The electric machine 10 istypically in the form of an electric generator or an electric motor. Forexpediency the machine 10 will be described hereinafter as a motor 10.It should be appreciated that a motor may operate as a generator andvice versa. The electric machine or motor 10 includes a housing 12. Thehousing 12 has an inner surface defining a cavity 14 therein.

Typically, the motor 10 includes a centrally located shaft 16 thatrotates relative to the housing 12. The electric machine also includes arotor 18. Typically, and as shown in FIG. 1, the rotor 18 includes theshaft 16 to which a load, not shown, is typically directly or indirectlysecured. As shown, the rotor 18 is rotatably secured to the housing 12.

As shown in FIG. 1, the motor 10 includes a stator 20 secured to thehousing 12. The stator 20 includes a stator body 22 that has a generallycircular outer periphery 24 and a generally circular inner periphery 26,spaced from the outer periphery 24.

While the body 22 may be made of various suitable materials, may beunitary or made from multiple components, as shown in FIG. 1, typically,the body 22 is made from a plurality of sheets or laminations 28. Thelaminations 28 are typically made of a magnetically conductive material,for example, of a ferrous material or a magnetically conductivecomposite. Each of the laminations 28 includes a plurality of spacedapart teeth 30 extending inwardly from the circular inner periphery 26.

The stator 20 also includes wire 39 formed into a plurality of coils 34,each of the plurality of coils 34 is wrapped around one of the pluralityof teeth 30.

Note that the above description of the motor 10 is for a radial fluxmotor. It should be appreciated that the actuator of the presentinvention may be utilized with an axial flux motor with or without arotor shaft. Such an axial flux motor is more fully described in U.S.Pat. No. 3,568,978 A, hereby incorporated in its entirety by reference.

For the induction, capacitive start, motor 10, the motor includes afirst set 32 of coils 34 that is used to operate the motor in a run modeand a second set 36 of coils 34 that are electrically connected to astart capacitor 38 that is used to operate the motor in a start mode.Once the motor reaches 70% of the motor maximum speed, the start coilsare deenergized with, for example, the centrifugal switch of the presentinvention.

According to an aspect of the present invention and referring now toFIG. 2, an electrical switch 40 for use in electric machine 10 mayinclude a first member 42 securable to the rotor 18 and rotatable withthe rotor 18. The switch 40 may also include a second member 44 slidablysecurable to the housing 12 and configured to be moveable with respectto the first member 42 in a direction parallel to axis of rotation 19 ofthe rotor 18. The first member 42 and the second member 44 are eithermagnetically attracted toward or magnetically repelled from each other.

As shown in FIG. 2, The first member 42 nay be attached to the rotor 18.As shown in FIG. 2, the first member 42 is attached to an end 46 of theshaft 16. The first member 42, as shown, may be attached along axis ofrotation 19. Placing the first member along the axis 19 minimizes anyout of balance forces on the rotating rotor 18.

To further minimize any out of balance forces on the rotating rotor 18,the first member has first member centerline 21 which is preferablycoincident with the axis of rotation 19 of rotor 18.

The first member may be secured to the shaft 16 and/or rotor 18 by acentrally located screw 48 attached by internal threads 49 formed inshaft 16. Alternatively, the first member may be secured by welding,adhesives or by an interference fit to shaft or rotor.

To provide the magnetic attraction or repulsion, the first member 42 orthe second member 44, or both, may include a magnet which provides forthe magnetic attraction or repulsion. The magnet may be permanentmagnet. The magnet may be a ferrite magnet or a rare earth magnet,including, for example a neodymium magnet.

As shown in FIG. 2, the first member 42 may have any shape and be madeof any suitable materials capable of being securable to the rotor 18 androtatable with the rotor 18.

The first member 42, as shown in FIG. 2, may have a portion thereof inthe form of a first member magnet 50.

It should be appreciated that the first member magnet 42 may be in theform of a unitary magnet, a cluster of adjacent magnets or a group ofspaced apart magnets.

Note that the first member 42 may alternatively not include a magnet,but only a ferrous material and the second member 44 would then includea magnet that cooperates with the ferrous material of the first member42.

The first member magnet 50 may be permanent magnet. The first membermagnet 50 may be a ferrite magnet or a rare earth magnet, including, forexample a neodymium magnet.

The first member magnet 50 may have any suitable shape. For example, thefirst magnet may be cylindrical, rectangular, square, polygon or anyother regular or irregular shape. As shown in FIG. 2, the first membermagnet 50 is cylindrical.

As shown in FIG. 2, the first member 42 may include a base 52 forsupporting the first member magnet 50. The base 52 may be integral withthe magnet 50 or be made of a different material.

As shown and according to an aspect of the invention the base 52 may bemade of a resilient material. The resilient material may be, forexample, a metal, a polymer or a composite. The base 52 may include amounting portion 54 for mounting the base 52 onto the shaft 16 or therotor 18. As shown in FIG. 2, the base may include one or more arms 56extending from the mounting portion 54.

Referring now to FIG. 3A, the first member magnet 50 has a center ofmass 58 moveable from a first radial distance FRD from the axis ofrotation 19 of the rotor 18 when the rotor 18 rotates at a firstrotational speed FRS to a second radial distance SRD from the axis ofrotation 19 of the rotor 18 when the rotor 18 rotates at a secondrotational speed SRS different than the first rotational speed FRS. Forexample and as shown in FIG. 3A, the first radial distance FRD may occurwhen the first rotational speed FRS is a zero rotational speed ZRS.

To have the center of mass 58 move and according to an aspect of theinvention, the base 52 is resilient so that the centrifugal force of thefirst member magnet 50 urges the magnet 50 radially outwardly anincreasing distance from the axis of rotation 19 of the rotor 18 as therotational speed of the rotor increases.

For example and as is shown in FIG. 3A, the arm 56 and the mountingportion 54 may be made of a resilient material such that when the rotor18 is stationary or at the first rotational speed FRS or at the zerorotational speed ZRS, the arm 56 and the mounting portion 54 are in astationary or first rotational speed position 60 as shown in solid.

As the rotor 18 begins to rotate and angularly accelerate, thecentrifugal forces on the first member 42 cause the center of mass 58 tomove from first radial distance FRD from axis of rotation 19 of rotor 18at the first rotational position 60 to second radial distance SRD fromaxis of rotation 19 of rotor 18 at second rotational speed position 62as shown in dashed lines when the rotor obtains a second rotationalspeed SRS.

As the rotor 18 continues to rotate and angularly accelerate, thecentrifugal forces on the first member 42 cause the center of mass 58 tomove from second radial distance SRD from axis of rotation 19 of rotor18 at second speed position 62 to third radial distance TRD from axis ofrotation 19 at third rotational speed position 64 as shown in phantomlines when the rotor 18 obtains a third rotational speed TRS.

According to an aspect of the invention, once the rotor 18 obtains thethird rotational speed TRS, the first member 42 cooperates with thesecond member 44 to either magnetically attract or magnetically repeleach other. This magnetic attraction or magnetic repulsion causes theelectrical switch 40 of the present invention to be tripped.

For the magnetic repulsion shown in FIGS. 1-5, the tripping at the thirdrotational speed position 64 is a tripping of a circuit that become“open” or prohibits electricity to be conducted. For example, thetripping can occur when third rotational speed TRS is 70% of the maximumrotor speed. At that 70% of the maximum rotor speed the second set orstarter coil set 36 may be deenergized by the tripping of electricalswitch 40 or prohibiting electricity to be conducted to the second setor starter coil set 36.

It should be appreciated that the third rotational speed TRS may be anypercentage of the maximum rotor speed and that the obtaining of thethird rotational speed TRS may trip the electrical switch 40 toaccomplish any desired change to the motor, for example to remove powerfrom the motor once a maximum rotor speed is exceeded.

It should be appreciated that the first member 42 may be configured toflex or move to permit the changing of the distance from the center ofmass of the magnet 50 to the axis of rotation 19 of rotor 18 by anyshape or configuration possible to permit this flexing. For example, themounting portion 54 may be generally rigidly positioned on shaft 16 bythe screw 48 connected to the shaft 16. The arm 56 may flex and/or aliving hinge 65 between the arm 56 and the mounting portion 54 may flexto permit the required movement of the magnet 50. The living hinge 65may have the same thickness as the arm 56 or the mounting portion 54 ormay have a thinner thickness to provide for most of the flexing in theliving hinge 65.

As shown in FIGS. 1-5, the switch 40 may also include the second member44 slidably securable to the housing 12 and is configured to be moveablewith respect to the first member 42 in a direction parallel to axis ofrotation 19 of the rotor 18. As the center of mass 58 of the firstmember magnet 50 decrease its distance from the axis of rotation 19 ofrotor 18, the first member magnet 50 becomes radially closer to thesecond member 44.

It should be appreciated that the first member 42 and the second member44 may either repel each other or attract each other. The switch 40 ofFIGS. 1-5 utilizes the first member 42 that repels the second member 44.

The second member 44 as shown in FIGS. 3-5 includes a second membermagnet 66. It should be appreciated that the second member magnet 66 maybe in the form of a unitary magnet, a cluster of adjacent magnets or agroup of spaced apart magnets.

It should be appreciated that the present invention may be practicedwith only a first member magnet or a second member magnet with the othermember having a ferrous material that may attract or repel the othermember.

As shown in FIG. 3A, the second member 44 is movable along a path asshown by arrows 67 constrained by, for example, a stem 68 secured to thehousing 12. This movement can be accomplished by any suitable mechanismproviding the restrained path.

As shown in FIG. 3A, the first member 42 urges the second member 44upwardly into stationary or upward position 55 as shown in solid whenthe rotor 18 is stationary. The actuator 40 also includes a downwardurging device 53 to urge the second member 44 downwardly to tripposition when the rotor 18 rotates sufficiently to trip the actuator 40.When the rotor 18 is stationary the magnetic repulsion force between thefirst member 42 and the second member 44 is greater than the force ofthe downward urging device 53 so that the second member 44 is instationary or upward position 55. When the rotor 18 rotates sufficientlyto trip the actuator 40, the magnetic repulsion force between the firstmember 42 and the second member 44 is less than the force of thedownward urging device 53 so that the second member 44 is in trip ordownward position 57, as shown in dashed lines.

The downward urging device 53 may be a spring, a sponge or gravity. Thedownward urging device 53 for the actuator 40 of FIGS. 1-5 is in theform of a first electrically conductive member 69, which will bediscussed in greater detail below.

For example and as shown in FIG. 3A, the stem 68 is mounted to housing12 and extends in axis 63 that may, as shown, be coincident with theaxis of rotation 19 of rotor 18. It should be appreciated that thepresent invention may be practiced with the stem extending in adirection skewed to the axis of rotation 19 or in a direction paralleland spaced from the axis of rotation 19 of rotor 18.

As shown in FIG. 3A as the first member 42 and first member magnet 50moves from first rotational position 60 to first position 62 andeventually to second position 64, the magnetic repulsion between thefirst member 42 and the second member 44 become less than the force ofthe downward urging device 53 which causes the second member 44 toadvance downwardly in the direction of arrows 67 along stem 68. Thesecond member 44 may have a central opening 45 which mates with theperiphery of the stem 68. The central opening 45 may be cylindrical orany other suitable shape. a cylindrical sleeve; and wherein the secondcomponent includes a cylindrical rod.

The motion of second member 44 downwardly provides the actuation forcefor the actuator or switch 40 of the present invention. As shown in FIG.3A, the switch 40 may also include the first electrically conductivemember 69 that cooperates with the second member 44. The firstelectrically conductive member 69 moves in a direction at leastpartially parallel to the axis 19 of rotation of the rotor 18 from afirst axial position 70 as shown in solid to a second axial position 71as shown in phantom, spaced from the first axial position 70.

The first electrically conductive member 69 may be biased downwardlytoward second position 71, so that the movement downwardly of the secondmember 44 permits the electrically conductive member 69 to move from thefirst axial position 70 to the second axial position 71. As stated abovethe first electrically conductive member 69 serves as the downwardurging device 53. The magnetic repulsion between the first member 42 andthe second member 44 is less than the downwardly urging firstelectrically conductive member 69, causing the first electricallyconductive member 69 to move downwardly.

Continuing to refer to FIG. 3A, the switch 40 may also include a secondelectrically conductive member 72 electrically engaged with the firstelectrically conductive member 69 when the first electrically conductivemember 69 is in the first axial position 70 and electrically disengagedwith the first electrically conductive member 69 when the firstelectrically conductive member 69 is in the second axial position 71.

When the second electrically conductive member 72 is electricallydisengaged from the first electrically conductive member 69, the switch40 may be tripped. The switch 40 is electrically connected to anelectric circuit 73 to affect the operation of the motor 10. Thisenergizing or tripping may cause the electric motor 10 to operatedifferently. For example, for the motor 10 if it is a capacitive startinduction motor, the tripping may occur when FRS is 70% of the maximumrotor speed and the circuit 73 may be tripped to disconnect power to thesecond set 36 of coils 34 and may cause the second set 36 of coils 34 orstarter coils to be deenergized.

The first electrically conductive member 69 and the second electricallyconductive member 72 may have suitable size and shape and may be made ofany suitable materials. The first and second members 69 and 72 may bemade of copper, aluminum or a composite material. The first and secondmembers 69 and 72 may have first and second contact portions 74 and 75,respectively, for engaging each other. The contact portions may be flatcurved, concave and convex, or have any other suitable configuration.

As shown in FIG. 3A, the first electrically conductive member 69 may bein the form of an electrically conductive plate or bar extending in acantilevered fashion from the housing 12 of motor 10. As shown thehousing 12 of motor 10 may include an end cap 76 to which the member 69is secured. As shown the member 69 extends from end cap 76 in adirection transverse to axis of rotation 19 of rotor 18. The firstelectrically conductive member 69 may be resilient such that it may bemoveable from first axial position 70 to second axial position 71. Themember 69 may have a contact portion made of a different or identicalmaterial and may have a shape conducive to good electrical conductancefrom the first member 69 to the second member 72. The first electricallyconductive member 69 has a distal portion 77 that engages second member44.

As shown in FIG. 3A, the second electrically conductive member 72 may bein the form of an electrically conductive plate or bar extending in acantilevered fashion from the end cap 76 to which the member 72 issecured. As shown the member 72 extends from end cap 76 in a directiontransverse to axis of rotation 19 of rotor 18.

The second electrically conductive member 72 may be resilient, but maybe rigid as the first electrically conductive member 69 is moveabletoward the second electrically conductive member 72. The member 72 mayhave a contact portion made of a different or identical material and mayhave a shape conducive to good electrical conductance from the firstmember 69 to the second member 72.

As shown in FIG. 3A, the contact portion 75 of the first electricallyconductive member 70 and the contact portion 76 of the secondelectrically conductive member 71 may have convex mating surfaces toprovide for an electric contact that will have no or minimal arcing asthe switch 40 is actuated.

It should be appreciated that the position of the stem, the strength ofthe downward urging device, the upward position 55 and the downwardposition 57 of the second member, the first rotational position 60 andthe second rotational speed position 64 of the first member, the sizeand magnetic strength of the first member and the second member 44, aswell as the dimensions of the first member base 52, may be modified toobtain the desired tripping or actuation for the actuator 40.

It should be appreciated that the position of the first member and/orthat of the second member may be made adjustable so that the trip oractuation speed of the actuator of the present invention may befine-tuned or adjusted for different motor applications. For example,the magnet may have an eccentric stem (not shown) that may be rotated toadjust magnet position, or the first member base may provide foradjustable magnet mounting (not shown) or for adjustment to arm lengthor arm flexibility (not shown).

Referring now to FIG. 4, the first member 42, the first member magnet50, the first member base 52 and the second member 44 are shown in thefirst rotational position 60.

Referring now to FIG. 5, the first member 42, the first member magnet50, the first member base 52 and the second member 44 are shown in thesecond rotational speed position 64.

While the actuator 40 of FIGS. 1-5 has a pair of spaced apart firstmembers 42, it should be appreciated that the actuator of the presentinvention may be provided with a solitary first member. The use of aplurality of first member spaced evenly about the center of rotation ofthe motor rotor may provide for smoother operation and for lower bearingloads and fewer balancing and vibration issues. Such problems with asolitary first member need to be balanced against the lower cost of asolitary first member.

According to another aspect of the invention and referring now to FIG.6, electrical switch 140 is shown. Switch 140 is similar to switch 40 ofFIGS. 1-5, except first member 142 includes a pair of spaced apart firstmember magnets 150 that are semi-cylindrically shaped. Each of themagnets 150 are connected to an arm 156 of base 152. Flat surfaces 147of the magnets 150 are positioned adjacent to each other.

According to another aspect of the invention and referring now to FIG.7, electrical switch 240 is shown. Switch 240 is similar to switch 40 ofFIGS. 1-5, except first member 242 includes a pair of spaced apart firstmember magnets 250 that are rectangularly shaped. Each of the magnets250 are connected to an arm 256 of base 252. Flat surfaces 247 of themagnets 250 are positioned adjacent to each other.

According to another aspect of the invention and referring now to FIG.8, electrical switch 340 is shown. Switch 340 is similar to switch 40 ofFIGS. 1-5, except first member 342 includes three equally of spacedapart first member magnets 350 that are cylindrically shaped. Each ofthe magnets 250 are connected to one of three arms 356 of base 352.

According to another aspect of the invention and referring now to FIG.9, electrical switch 440 is shown. Switch 440 is similar to switch 40 ofFIGS. 1-5, except first member 442 includes four equally of spaced apartfirst member magnets 450 that are cylindrically shaped. Each of themagnets 450 are connected to one of four arms 456 of base 452.

According to another aspect of the invention and referring now to FIG.10, electrical switch 540 is shown. Switch 540 is similar to switch 40of FIGS. 1-5, except first member 542 includes two equally of spacedapart first member magnets 550 that are cylindrically shaped. Each ofthe magnets 550 are connected to one of the two arms 556 of base 552.Second member 544 with a second member magnet 566 is slidably fitted tohousing 512 at stem 568 of second member 544.

An additional magnet 580 is secured by screw 548 to shaft 516 and tofirst member base 552. The additional magnet 580 may be used to attractor repel the second member magnet 566. The additional magnet 580 mayprovide for more “snap” or more aggressive movement of the firstelectrically conductive member to the second electrically conductivemember to reduce arcing and to prolong the life of the actuator. Notethat additional magnet(s) may be position at other locations in themotor, particularly in the first member base to improve this “snap”action. Also, the strength and positioning of the magnets may beadjusted to improve this “snap” action.

According to another aspect of the invention and referring now to FIG.11, electrical switch 640 is shown. Switch 640 is similar to switch 40of FIGS. 1-5, except that switch 640 using the magnetic attraction ofthe first member 642 to the second member 644 to actuate the switch 640.The first member 642 includes two equally of spaced apart first membermagnets 650 that are cylindrically shaped. Each of the magnets 650 areconnected to one of the two arms 656 of base 652. Second member 644 witha second member magnet 666 is slidably fitted to housing 612 at stem 668of second member 644. The second member magnet 666 is positioned belowthe two first member magnets 650.

When in the stationary or zero rotational speed position 660 as shown,the two first member magnets 650 urge second member magnet 666 and thesecond member 644 upwardly to connect the first electrically conductivemember to the second electrically conductive member. As arms 656 of thefirst member base 652 move outwardly as the rotor 618 rotates, the firstmember magnets 650 provide less upward magnetic attraction to the secondmember magnet 666, letting the second member 644 move downwardlypermitting the first electrically conductive member to disconnect fromthe second electrically conductive member.

According to another aspect of the invention and referring now to FIG.12, electrical switch 740 is shown. Switch 740 is similar to switch 40of FIGS. 1-5, except first member 742 includes a plurality of spacedapart first member magnet segments 750 that are arch shaped. Each of themagnets magnet segments 750 are positioned at a radial distance RD fromcenterline 781 of base 752. Second member 744 with a second membermagnet 766 is slidably fitted to housing 712 at stem 768 of secondmember 744. The stem 768 is positioned on stem centerline 782 parallelto axis of rotation 719 of rotor 718. The centerline is spaced radialdistance RDD from axis of rotation 719 of rotor 718. Centerline 781 ofbase 752 may be coincident with axis of rotation 719 of rotor 718.

According to another aspect of the invention and referring now to FIGS.13-14, electrical switch 840 is shown. Switch 840 is similar to switch40 of FIGS. 1-5, except first member 842 includes a pair of spaced apartfirst member magnets 850 that are mounted to first member base 852. Themagnets 850 are each mounted to one of a plurality of arms 856.

The first member base 852 is made from a plurality of individualmembers. The first member base 852 includes first member mounting plate884 which is secured to rotor 818. The first member base 852 alsoincludes the spaced apart arms 856 that are connected to first membermounting plate 884 by mechanical hinges 886. The arms 856 are urgedinwardly by a spring 888. The spring 888 is connected to the arms 856.

The spring 888 is adapted to permit the arms 856 to move outwardly aboutthe hinge when the rotor 818 is rotated. As the arms 856 move outward asthe rotor continues to rotationally accelerate, the first member magnets850 move away from second member magnet 866 connected to second member844 that is slidably fitted to housing 812 and moves downwardlypermitting the first electrically conductive member to disconnect fromthe second electrically conductive member.

According to an aspect of the invention a method 900 for transmitting anelectrical signal in an electric machine once a certain rotation speedhas been obtained is provided. The method includes step 910 of providinga housing, step 912 of securing a stator to the housing, and step 914 ofrotatably securing a rotor to the housing. The rotor defines an axis ofrotation thereof.

The method also includes step 916 of providing a centrifugal switch,step 918 of securing a first member to the rotor, and step 920 ofslidably securing a second member to the housing.

The method also includes the step 922 of configuring the second memberto be moveable with respect to the first member in a direction parallelto the axis of rotation of the rotor, step 924 of adapting of the firstmember and the second member to be one of magnetically attracted towardor magnetically repelled from each other, and step 926 of providing afirst electrically conductive member.

The method also includes the step 928 of using the second member toselectively move the first electrically conductive member from the firstaxial position to the second axial position, step 930 of providing asecond electrically conductive member spaced from the first electricallyconductive member when the first electrically conductive member is inthe first axial position, and step 932 of electrically engaging with thefirst electrically conductive member to the second electricallyconductive member when the first electrically conductive member is inthe second axial position.

The method also includes step 934 of providing a portion of the firstmember having a center of mass moveable from a first radial distancefrom the axis of rotation of the rotor when the rotor rotates at a firstrotational speed to a second radial distance from the axis of rotationof the rotor when the rotor rotates at a second rotational speeddifferent than the first rotational speed, the second radial distancebeing different than the first radial distance.

The method also includes step 936 of utilizing one of the of magneticattraction and the magnetic repulsion to cause one of the first memberand the second member to be one of magnetically attracted toward eachother or magnetically repelled away from each other to cause the secondmember to engage the first electrically conductive member with thesecond electrically conductive member when the rotor reaches one of thefirst rotational speed and the second rotational speed. The inner cavityis generally cylindrical and wherein the moisture guide is generallyplanar.

The methods, systems, and apparatus described herein facilitateefficient and economical assembly of an electric machine. Exemplaryembodiments of methods, systems, and apparatus are described and/orillustrated herein in detail. The methods, systems, and apparatus arenot limited to the specific embodiments described herein, but rather,components of each apparatus and system, as well as steps of eachmethod, may be utilized independently and separately from othercomponents and steps described herein. Each component, and each methodstep, can also be used in combination with other components and/ormethod steps.

When introducing elements/components/etc. of the methods and apparatusdescribed and/or illustrated herein, the articles “a”, “an”, “the”, and“the” are intended to mean that there are one or more of theelement(s)/component(s)/etc. The terms “comprising”, “including”, and“having” are intended to be inclusive and mean that there may beadditional element(s)/component(s)/etc. other than the listedelement(s)/component(s)/etc.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

Described herein are exemplary methods, systems and apparatus utilizinglower cost materials in a permanent magnet machine that reduces oreliminates the efficiency loss caused by the lower cost material.Furthermore, the exemplary methods system and apparatus achieveincreased efficiency while reducing or eliminating an increase of thelength of the machine. The methods, system and apparatus describedherein may be used in any suitable application. However, they areparticularly suited for HVAC and pump applications.

Exemplary embodiments of the fluid flow device and system are describedabove in detail. The electric machine and its components are not limitedto the specific embodiments described herein, but rather, components ofthe systems may be utilized independently and separately from othercomponents described herein. For example, the components may also beused in combination with other machine systems, methods, andapparatuses, and are not limited to practice with only the systems andapparatus as described herein. Rather, the exemplary embodiments can beimplemented and utilized in connection with many other applications.

Although specific features of various embodiments of the disclosure maybe shown in some drawings and not in others, this is for convenienceonly. In accordance with the principles of the disclosure, any featureof a drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. An electrical switch for an electric machinehaving body, a stator fixedly secured to the body and a rotor rotatablysecured to said body and defining an axis of rotation thereof, saidactuator comprising: a first member securable to said rotor androtatable therewith; a second member slidably securable to the body andconfigured to be moveable with respect to said first member in adirection parallel to the axis of rotation of the rotor, said firstmember and said second member being one of magnetically attracted towardor magnetically repelled from each other; a first electricallyconductive member cooperable with said second member moveable in adirection parallel to the axis of rotation of the rotor from a firstaxial position to a second axial position, spaced from the first axialposition, said second member adapted to urge said first electricallyconductive member from the first axial position to the second axialposition; a second electrically conductive member spaced from said firstelectrically conductive member when said first electrically conductivemember is in the first axial position and electrically engaged with saidfirst electrically conductive member when said first electricallyconductive member is in the second axial position, said first memberhaving a least a portion thereof having a center of mass moveable from afirst radial distance from the axis of rotation of the rotor when therotor rotates at a first rotational speed to a second radial distancefrom the axis of rotation of the rotor when the rotor rotates at asecond rotational speed different than the first rotational speed, thesecond radial distance being different than the first radial distance,one of the of magnetic attraction and the magnetic repulsion causing thesaid first member and said second member to be one of magneticallyattracted toward each other or magnetically repelled away from eachother to cause to cause the second member to one of engage and disengagethe first electrically conductive member with the second electricallyconductive member when the rotor reaches the second rotational speed. 2.The electrical switch as in claim 1, where said first member and saidsecond member are magnetically repelled by each other.
 3. The electricalswitch as in claim 1, wherein at least one of a portion of said firstmember and a portion of said second member comprises a magnet.
 4. Theelectrical switch as in claim 1, wherein said first member comprises: abase fixedly secured to the end of the rotor; an arm having an endextending from the base at least partially in a direction parallel tothe axis of rotation of the rotor; and one of a magnet and a ferrousmaterial connected to the end of the arm and spaced from the base. 5.The electrical switch as in claim 1, wherein said first membercomprises: a plurality of spaced apart arms, each arm having a first endthereof; and one of a magnet and a ferrous material connected to thefirst end of each of the plurality of arms.
 6. The electrical switch asin claim 5, wherein each of the spaced apart arms are equally spacedapart with respect to the axis of rotation of the rotor
 7. Theelectrical switch as in claim 1, wherein said second member comprises: afirst component fixedly secured to said body; a second componentslidably secured to said first component; and one of a magnet and aferrous material secured to said second component.
 8. The electricalswitch as in claim 7: wherein the first component comprises acylindrical sleeve; and wherein the second component comprises acylindrical rod.
 9. The electrical switch as in claim 1, wherein saidfirst electrically conductive member comprises a resilient metal havinga first end connected to the body and a second cantilevered endengagable with said second member; and wherein said second electricallyconductive member comprises a resilient metal having a first endconnected to the body and a second cantilevered end engagable with saidfirst electrically conductive member.
 10. The electrical switch as inclaim 1, wherein said first member comprises: a first componentincluding a base fixedly secured to the end of the rotor, first andsecond legs, each leg extending at least partially axially outwardlyfrom one of the distal ends of the planar base and first and secondplanar arms extending at least partially radially inwardly from thedistal ends of the legs; one of a magnet and a ferrous materialconnected to the first arm; and the other of one of a magnet and aferrous material connected to the second arm.
 11. The electrical switchas in claim 10, wherein the ferrous material is permanently magnetized.12. The electrical switch as in claim 10; wherein the first component ismade from a plurality of individual members; wherein the first arm isconnected to the first leg by a mechanical hinge; and further comprisinga spring connected to the first leg and to the second arm, said springadapted to permit the first arm to move outwardly about the hinge whenthe rotor is rotated.
 13. The electrical switch as in claim 1: whereinthe first member includes a first member magnet; and further comprisinga third member including a third member magnet, the third memberconnected to said first member, the third member magnet positionedfarther than first member magnet from the second member.
 14. Theelectrical switch as in claim 1, wherein said first member comprises: anintegral metal component having a planar base fixedly secured to the endof the rotor, first and second planar legs, each leg extending at leastpartially axially outwardly from one of the distal ends of the planarbase and first and second planar arms extending at least partiallyradially inwardly from the distal ends of the planar legs; a firstmagnet connected to the first arm; and a second magnet connected to thesecond arm.
 15. The electrical switch as in claim 14, further comprisinga third magnet positioned on the planar base of said component.
 16. Theelectrical switch as in claim 1: wherein said first member includes aplurality of spaced apart arcuate magnet portions spaced from the axisof rotation of the rotor; and wherein said second member has acenterline parallel to and spaced from the axis of rotation of therotor.
 17. An electric machine, comprising: a housing, said housinghaving an inner surface defining a cavity therein; a stator secured tosaid housing; a rotor, rotatably secured to said housing and defining anaxis of rotation thereof; and a centrifugal switch including: a firstmember securable to said rotor and rotatable therewith; a second memberslidably securable to the body and configured to be moveable withrespect to said first member in a direction parallel to the axis ofrotation of the rotor, said first member and said second member beingone of magnetically attracted toward or magnetically repelled from eachother; a first electrically conductive member cooperable with saidsecond member moveable in a direction parallel to the axis of rotationof the rotor from a first axial position to a second axial position,spaced from the first axial position, said second member adapted to urgesaid first electrically conductive member from the first axial positionto the second axial position; and a second electrically conductivemember spaced from said first electrically conductive member when saidfirst electrically conductive member is in the first axial position andelectrically engaged with said first electrically conductive member whensaid first electrically conductive member is in the second axialposition, said first member having a least a portion thereof having acenter of mass moveable from a first radial distance from the axis ofrotation of the rotor when the rotor rotates at a first rotational speedto a second radial distance from the axis of rotation of the rotor whenthe rotor rotates at a second rotational speed different than the firstrotational speed, the second radial distance being different than thefirst radial distance, one of the of magnetic attraction and themagnetic repulsion causing the said first member and said second memberto be one of magnetically attracted toward each other or magneticallyrepelled away from each other to cause to cause the second member to oneof engage and disengage the first electrically conductive member withthe second electrically conductive member when the rotor reaches thesecond rotational speed.
 18. The electric machine as in claim 17,wherein said first member and said second member are magneticallyrepelled by each other.
 19. The electric machine as in claim 17, whereinat least one of a portion of said first member and a portion of saidsecond member comprises a magnet.
 20. A method for transmitting anelectrical signal in an electric machine once a certain rotation speedhas been obtained, the method comprising the steps of: providing ahousing; securing a stator to said housing; rotatably securing a rotorto the housing, the rotor defining an axis of rotation thereof; andproviding centrifugal switch, wherein providing the switch includes;securing a first member to the rotor; slidably securing a second memberto the housing; configuring the second member to be moveable withrespect to the first member in a direction parallel to the axis ofrotation of the rotor; adapting the first member and the second memberto be one of magnetically attracted toward or magnetically repelled fromeach other; providing a first electrically conductive member; using thesecond member to selectively move the first electrically conductivemember from the first axial position to the second axial position;providing a second electrically conductive member spaced from the firstelectrically conductive member when the first electrically conductivemember is in the first axial position; electrically engaging with thefirst electrically conductive member to the second electricallyconductive member when the first electrically conductive member is inthe second axial position, the first member; providing a portion of thefirst member having a center of mass moveable from a first radialdistance from the axis of rotation of said rotor when said rotor rotatesat a first rotational speed to a second radial distance from the axis ofrotation of said rotor when said rotor rotates at a second rotationalspeed different than the first rotational speed, the second radialdistance being different than the first radial distance; and utilizingone of the of magnetic attraction and the magnetic repulsion to causeone of the first member and the second member to be one of magneticallyattracted toward each other or magnetically repelled away from eachother to cause the second member to engage the first electricallyconductive member with the second electrically conductive member whensaid rotor reaches one of the first rotational speed and the secondrotational speed.